Purge temporary on restore, no purge on failed restore.

Author: evoskuil

include/bitcoin/database/impl/store.ipp

@@ -1048,17 +1048,21 @@ code CLASS::restore(const event_handler& handler) NOEXCEPT
     static const auto heads = configuration_.path / schema::dir::heads;
     static const auto primary = configuration_.path / schema::dir::primary;
     static const auto secondary = configuration_.path / schema::dir::secondary;
+    static const auto temporary = configuration_.path / schema::dir::temporary;
 
     handler(event_t::recover_snapshot, table_t::store);
 
+    // Clean up any residual /temporary.
+    file::clear_directory(temporary);
+    file::remove(temporary);
+
     if (file::is_directory(primary))
     {
         // Clear invalid /heads, recover from /primary, clone to /primary.
         ec = file::clear_directory_ex(heads);
         if (!ec) ec = file::remove_ex(heads);
         if (!ec) ec = file::rename_ex(primary, heads);
         if (!ec) ec = file::copy_directory_ex(heads, primary);
-        if (ec) /* bool */ file::remove_ex(primary);
     }
     else if (file::is_directory(secondary))
     {
@@ -1067,7 +1071,6 @@ code CLASS::restore(const event_handler& handler) NOEXCEPT
         if (!ec) ec = file::remove_ex(heads);
         if (!ec) ec = file::rename_ex(secondary, heads);
         if (!ec) ec = file::copy_directory_ex(heads, primary);
-        if (ec) /* bool */ file::remove_ex(secondary);
     }
     else
     {